Transformers Animated episode 12, Survival of the Fittest, first aired in the US on March 8th 2008. The episode features Meltdown and the Dinobots, including the first appearance of Snarl and Swoop in robot mode. Also shown are two organic creatures based on the Generation One Pretenders Submarauder and Bombburst.

Episode Guide
The episode starts at the Autobot's base where Prowl is teaching Sari some "ninja nerve holds" in order to protect herself. After recent events, including the attach by Blitzwing and Lugnut, the Autobots are concerned that Sari will become a primary target for the Decepticons. After a little training the scene jumps to the Sumdac Towers and Sari's bedroom, where she continues to practice her moves before going to bed. After a short time she is awoken by a shadow and movement from outside her window. As she goes to investigate a silhouette of the Dinobot Swoop appears. Her father, Issac Sumdac, enters her room bring in milk and cookies, discovering that his daughter is missing!

Issac calls both the Autobots and the police to investigate Sari's disappearance, and there is some nice banter between Captain Fanzone and one of the DPD Police Officers, and later Prowl. As the Autobots and Fanzone look at some CCTV footage, Prowl and Bulkhead discuss telling Optimus Prime about the Dinobots. Captain Fanzone notices the two whispering and decides to follow them himself.

As Prowl and Bulkhead make there way to "Dinobot Island", a deserted research station in the middle of Lake Eerie, Captain Fanzone tails them in a mini-sub. His failure to get on with technology is highlighted in another comical scene. As Bulkhead and Prowl discover that the Dinobots are no-longer in the volcano the scene jumps to a hidden labratory where the Dinobots are, along with Meltdown (who is now controlling them). Cyrus Rhodes is also there along with a captured Sari, who Meltdown plans on using as an experiment. As Bulkhead and Prowl look for the Dinobots, Captain Fanzone gets caught in some quicksand and has to call out for help, revealing that he has been following the two Autobots. As they pull Fanzone to saftey the Dinobots, Grimlock, Snarl and Swoop turn up and attack the three, much to the suprise of Prowl.
As Bulkhead takes out both Grimlock and Snarl, Prowl discovers bun marks on the legs of Swoop, prompting him to conclude that Meltdown is involved. Bulkhead then takes down Swoop (meaning the big green robot has defeated the entire Dinobots), before a second assault commences. The Autobots, along with Fanzone, try to escape, ending up in a deadend. Meltdown then reveals himself to the Autobots, burning Bulkhead who is almost taken offline and capturing Prowl and Fanzone.

Prowl and Fanzone awake in a prison, where Meltdown reveals his cunning plan to create a transforming human, using Sari Sumdac as his latest test subject. He then reveals two previous attempts, one of which was his layer, who are now monsters. The creatures are based visually on Bombburst and Submarauder (shown on the Transformers Animated concept sketches) which is a nice nod to the G1 series. As the two creatures attack Prowl and Fanzone the scene jumps again to Sari and Cryus. Sari has convinced Cyrus that she needed a toliet break (again) and has been using the time to create an escape plan. Calling Cyrus into the restroom she uses her Allspark key on the toliet, disrupting the electro's in Cyrus' boosters disabling his "bulk-up" power. Sari then escapes and find her way to the cell in which Prowl and Fanzone are captured. Turning off the electro bars, the pair escape, picking up Sari on the way and make their way to the surface. Captain Fanzone also picks up a protective clothing, which looks like Meltdown's costume, on the way.

Now outside, Sari uses the Allspark key (again) to fix Bulkhead, before Meltdown and the Dinobots appear. Sari distracts Meltdown and Prowl knocks him to the ground, allowing Captain Fanzone to capture the super-villan using the protective clothing (now looking more like a sheet). As the Dinobots prepare to save their new master, Prowl reminds them that Meltdown is no longer a threat. The Dinobots understand and the three Transform, much to the suprise of everyone, to extract their revenge on Meltdown. At this point Cyrus (in bulked up mode), Bombburts and Submaraurder (not their real names) appear, and the Dinobots quickly dispatch of them.

The final scenes showin the Autobots (Bulkhead and Prowl), Captain Fanzone and Sari making their way from Dinobot Island on a boat. Fanzone agrees he will not tell anyone of the Dinobots, and Bulkhead and Prowl discuss telling Prime. Sari goes back to practicing her ninja-technique on Bulkhead, to "sells" the injury and the episode ends.

Note: The wrong credits aired with this episode, the credits used were from Episode 11 Lost and Found, which include listings for Blitzwing, Lugnut and Starscream.